feat: add TYPE/STRUCT and DATA_BLOCK support to tree-sitter grammar

- Add type_definition rule for UDT files (TYPE/STRUCT/END_STRUCT/END_TYPE)
- Add data_block rule for DB files (DATA_BLOCK/BEGIN/END_DATA_BLOCK)
- Add NON_RETAIN and RETAIN modifiers support in data blocks
- Keywords now highlighted correctly in .udt and .db files

grammar.js

@@ -28,10 +28,40 @@ module.exports = grammar({
         $.organization_block,
         $.function_block,
         $.function,
+        $.type_definition,
+        $.data_block,
         $.statement
       )
     ),
     
+    type_definition: $ => seq(
+      alias('TYPE', $.keyword),
+      field('name', choice($.string, $.identifier)),
+      optional(seq(alias('TITLE', $.keyword), '=', choice($.string, $.identifier))),
+      optional($.attribute_list),
+      optional(seq(alias('VERSION', $.keyword), ':', $.number)),
+      alias('STRUCT', $.keyword),
+      repeat(choice($.var_item, $.block_comment)),
+      alias('END_STRUCT', $.keyword),
+      alias('END_TYPE', $.keyword)
+    ),
+    
+    data_block: $ => seq(
+      alias('DATA_BLOCK', $.keyword),
+      field('name', choice($.string, $.identifier)),
+      optional(seq(alias('TITLE', $.keyword), '=', choice($.string, $.identifier))),
+      optional($.attribute_list),
+      optional(seq(alias('VERSION', $.keyword), ':', $.number)),
+      optional(choice(
+        alias('NON_RETAIN', $.keyword),
+        alias('RETAIN', $.keyword)
+      )),
+      optional($.var_declaration),
+      alias('BEGIN', $.keyword),
+      repeat($.statement),
+      alias('END_DATA_BLOCK', $.keyword)
+    ),
+    
     organization_block: $ => seq(
       alias('ORGANIZATION_BLOCK', $.keyword),
       field('name', $.string),